Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when it's the best time to plant catharanthus by referring to the USDA zone info for Walnut Ridge.

Planting Calendar for Catharanthus

Frost tolerance for catharanthus:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since catharanthus require warm weather you must wait until after the last frost before you can plant them.

The earliest that you can plant catharanthus in Walnut Ridge is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant catharanthus and expect a good harvest is probably August. Any later than that and your catharanthus may not have a chance to grow to maturity. If you are starting your catharanthus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Walnut Ridge the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Walnut Ridge may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Walnut Ridge last frost occurs after April 15 be ready to protect your catharanthus in the event of a late frost.

USDA Zone Info for Walnut Ridge

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Walnut Ridge

You may be interested in your other planting guides for Walnut Ridge.